Quantum Dot Color Conversion Unit with Non-Uniform Blue Light Blocking Filter
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Solution Overview
Problem
Liquid crystal display (LCD) devices have low luminous efficiency due to the use of color filters, which increases manufacturing costs and complexity, particularly in photo-luminescent LCDs that employ quantum dot color conversion layers.
Innovation Solution
A color conversion unit is introduced, comprising a first, second, and third color converting member on a substrate, with a blue light blocking filter that is thicker at the boundary than at the center, and a coating layer with hydrophobicity, to convert blue light into red and green light, reducing manufacturing costs and time by simplifying processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If color filters are used in LCD devices, then color reproduction is achieved, but luminous efficiency decreases due to light absorption
Solution Approach 1:
The patent replaces traditional color filters with a quantum dot color conversion layer that converts blue light into red and green light through photoluminescence. This quantum dot layer changes the color of incident light rather than filtering it, thereby improving luminous efficiency while maintaining color reproduction quality.
2Reliability
If photo-luminescent LCD devices use quantum dot color conversion layers, then color reproduction improves, but manufacturing costs and process complexity increase due to additional photo processes
Solution Approach 1:
The patent combines the quantum dot color conversion layer with the liquid crystal layer into a single integrated structure. The quantum dot layer is positioned between the backlight unit and the liquid crystal layer, merging two previously separate components into one unified assembly, thereby simplifying the manufacturing process while maintaining color conversion functionality.
3Ease of manufacture
If a uniform blue light blocking filter is used, then manufacturing is simple, but light leakage at boundaries between color converting members reduces display quality
Solution Approach 1:
The patent applies a non-uniform thickness design to the blue light blocking filter, making it thicker at the boundary portions between color converting members and thinner at the center portions. This local variation in filter thickness provides enhanced light blocking at critical boundary areas while maintaining manufacturing feasibility, thereby improving display quality without excessive complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enhances luminous efficiency and reduces manufacturing costs by simplifying the panel manufacturing process while maintaining high color reproducibility, addressing the inefficiencies of traditional LCDs and photo-luminescent LCDs.
Implementation Method 1
Photo-luminescent liquid crystal display (PL-LCD) devices... display color images by using visible light which is generated when light of a low wavelength range, such as ultraviolet light or blue light, emitted from a light source and controlled by a liquid crystal layer, is irradiated to a color conversion layer (CCL)
Implementation Method 2
a blue light blocking filter located to overlap the second color converting member and the third color converting member
Implementation Method 3
The first color converting member may further include a coating layer having hydrophobicity against the blue light blocking filter
Data Source
AI summary
A display device including: a display panel; a light source providing light to the display panel; and a color conversion unit converting a color of the light incident from the light source into a different color. The color conversion unit includes: a first color converting member, a second color converting member, and a third color converting member, located on a substrate, which convert the color of the light incident from the light source into different colors from each other, respectively, and output the lights having converted colors; and a blue light blocking filter located to overlap the second color converting member and the third color converting member. The blue light blocking filter is thicker at a boundary portion than at a center portion thereof.